Evaluation of the nutritive value of selected South Sudan rangeland browses fed to crossbred growing goats

Abstract

More than 78% of the households own livestock in South Sudan. Livestock, particularly cattle, goats and sheep, are an important social and economic asset in South Sudan. Goats are important and are predominant in most rural households with estimated population of 12.5 million heads. Despite the vast potential livestock contribution to the rural household development, livestock products (milk and meat) do not meet the local demands due to low productivity. The available seasonal feed resources are usually scarce, fibrous and deficient of essential nutrients, this is undermining livestock production and as well threatening the livelihoods of more than 78% of South Sudan’s population. A study was designed to evaluate alternative feed resources to be included in designing nutrition packages for small ruminants to improve herd productivity. The selected South Sudan browse species namely, Grewia tenax, Balanites aegyptiaca, Cordia sinensis, Tamarindus indica, Ziziphus spina-christi and Kedrostis foetidissima were studied on the basis of proximate composition, in vitro gas production, palatability and the effect on intake, digestibility and body weight change of goats. In palatability, five of the above mentioned browse species were used except K. foetidissima whereas in performance (intake, digestibility and daily gain) an experiment was conducted in Completely Randomized Design (CRD) using twelve crossbred (Small East African x Toggenburg) growing goats assigned randomly to 3 treatments (C. gayana=control; Control+200g/d of G.tenax and Control+200g/d Z. spina-christi). The proximate composition showed differences (P<0.05) from 130-224 CP, 292-423 NDF, 172-356 ADF, 85.2-142 Ash, 858-976 OM, and 29.3-96.7 EE except DM (P>0.05). Condensed tannins varied moderately except T. indica which was observed to be highest in condensed tannin (≥60g/kg DM). Mineral concentrations varied from species with abundant quantities. After 24 and 48 hours incubation time, Z. spina-christi recorded the highest rate of gas production (20.9%/h) and potential gas production (9.56ml/200mg DM) while the lowest rate was in T. indica and the lowest gas production was in B. aegyptiaca. In Palatability, G. tenax was ranked the highest both in average daily intake (134g/kg DM/goat/day) and relative palatability index (76.1%). The results of supplementation showed higher dry matter intake and average daily gain for supplemented than non-supplemented goats. It was concluded that G. tenax was the highest in CP, most palatable and with the highest average daily gain (34.1g/day) when supplemented to poor quality C. gayana hay, and thus can be used to supplement low quality basal diet.